In the semiconductor wafer fabrication process, a chemical mechanical polishing (abbreviated as CMP) process is widely used to polish the wafer so as to planarize the surface of the wafer. In a common CMP process, a polishing pad (or abrasive pad) fixed at a rotary table is used to contact with and apply a force to a silicon wafer carried on a spinning carrier. The carrier and the rotary table are rotated, while a polishing slurry is supplied to the polishing pad during polishing. In general, fragments derived by polishing and the polishing slurry are accumulated in pores of the polishing pad, such that the polishing pad is consumed and the polishing effect on wafer is then reduced. Therefore, it is necessary to use a conditioner for the removal of fragments and polishing slurry remained in the polishing pad.
In a conventional CMP conditioner using diamond particles as polishing material, such as that in Taiwan patent no. 575477 disclosing a CMP conditioner comprising a support member, and a plurality of hard abrasive grains provided on a surface of the support member, it is characterized in that the plurality of hard abrasive grains are regularly arranged on the surface of the support member, in which the hard abrasive grains are diamond particles. In another CMP conditioner using chemical vapor deposition (CVD) diamonds, such as that in Taiwan patent publication no. 200948533 proposing a non-planar CVD diamond-coated CMP pad conditioner and method for manufacturing same, it is primary to disclose a conditioning head comprising a chemical vapor deposited diamond composite, the conditioning head further comprising: (a) a non-coated substrate comprising a surface of substrate, the substrate further comprising: (1) a first phase comprising at least one ceramic material; and (2) a second phase comprising at least one carbide-forming material, in which the surface of substrate comprises at least one non-planar trimming region projecting out of the surface of substrate. Alternatively, in Taiwan utility model no. M275917 proposing a conditioner disk for use in chemical mechanical polishing, it is primary to disclose a conditioner disk for use on a polishing pad in chemical mechanical polishing process comprising a base structure and a plurality of blades, the base structure having an axial of rotation, the projecting blades being supported in a blade region by the base structure, each blade radiating outward from a central region of the base structure and extending tangentially, the blades extending in a common direction. Alternatively, in Taiwan utility model no. M510214, filed by the applicant, a chemical mechanical polishing conditioner comprising a substrate and multiple abrasive units is disclosed, the substrate having a top surface, the abrasive units being mounted on the substrate via a bonding layer. Each abrasive unit comprises a base of the abrasive unit and a polishing layer. The base of the abrasive unit is provided on a surface of the bonding layer opposite to the substrate. Moreover, considering the area of the top surface of the substrate as 100%, the area of the substrate covered by the base of the abrasive unit is in the range from 5% to 50%. The polishing layer is provided, on a surface of the base of the abrasive unit opposite to the bonding layer, with a plurality of tips.
In the above prior art, it is frequently prone to slice and clog the polishing pad, and further scratch wafers, due to the machining characteristic of diamond particles, in terms of chemical mechanical conditioner using diamond particles. Further, in terms of chemical mechanical conditioner using CVD diamonds, a base, a plurality of polishing substrates formed on the base, and CVD diamonds formed on the base of the abrasive units are in principle included in each case, as well as the CVD diamond is used as material for conditioning. In this case, with regard to the shape of the polishing substrate, the characteristic structure of the non-planar surface in Taiwan patent no. 200948533 may be presented in the form of linear or non-linear line segments, such as concentric rings, discontinuous or staggered concentric rings, spirals, discontinuous spirals, rectangles, discontinuous rectangles, irregular patterns, and etc., for example, discontinuous or continuous concentric rings together with spirals, or concentric rings together with spiral line segments. In Taiwan utility model no. M275917, the curved blades are extended in a radiating direction, while each blade is extended to the edge from a central region. In Taiwan utility model no. M510214, the base of the abrasive unit may be shaped as a hexagon, an arc, or another geometry. In the above chemical mechanical conditioner using CVD diamonds, although the problem of slicing the polishing pad may be eliminated, the impurities of chips are impossibly removed effectively. It is known from the above that the structure design of the chemical mechanical conditioner is still to be improved.